As disclosed in Patent Document 1, there is a conventional cylindrical battery that includes a battery case having a cylindrical shape, and an electrode group having a columnar shape and accommodated in the battery case. In the electrode group, belt-shaped positive and negative electrode plates are spirally wound with a belt-shaped separator being interposed therebetween.
In the battery in which the positive electrode plate, the negative electrode plate, and the separator in the belt shapes are spirally wound, the positive electrode plate and the negative electrode plate may be displaced in the winding step. In this case, there arise such problems that the cylindrical battery fails to achieve desired battery capacity, or internal short-circuit occurs.